Surgical apparatus for performing suction lipectomy

ABSTRACT

A cannula is provided with a guide bar, a rear end of which is formed with a mounting sleeve through which the cannula handle is clamped to the guide bar. The forward end of the guide bar carries a height adjustment bar having a pair of guide wheels rotatably mounted to a lower surface thereof between the guide bar and cannula tip. The height adjustment bar is provided with an elongate slot through which two screws pass for threaded connection to the forward end. Loosening of the screws permits the height adjustment bar to slide to vary the spacing between the guide wheels and cannula tip. The peripheral surface of each guide wheel is formed with an inner beveled edge that stretches the skin between the guide wheels during the suction lipectomy procedure enabling the cannula tip to travel at constant depth through the fatty tissue as the cannula is manually directed by the surgeon in reciprocating strokes.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 07/014,839,filed Feb. 13, 1987 now abandoned, which is a continuation of Ser. No.06/831,799, filed Feb. 21, 1986 now U.S. Pat. No. 4,676,780, which is acontinuation-in-part of PCT Appln. PCT/US85/00814, filed May 6, 1985.

1. Technical Field

The present invention relates generally to surgical instruments and,more particularly, to a surgical cannula and its method of use inperforming suction lipectomy to remove excessive accumulations of fattytissue from a human body.

2. Background Art

Suction lipectomy or lipolysis is a surgical procedure for removingfatty tissue and fatty tumors from localized areas of the human bodythrough small incisions that can be easily concealed. The surgicalprocedure customarily employed requires an incision in the skin toexpose the fatty tissue. The tip of a cannula is then inserted into theincision and manually directed by the surgeon towards the desired areaof the body By guiding the tip through the fatty tissue whilesimultaneously applying suction through a longitudinal passage extendingthrough the cannula in communication with the tip, fat is surgicallyaspirated from the body For adequate aspiration, approximately 15-20strokes of the tip through the fatty tissue are often necessary.

FIG. 1 is an illustration of a conventional cannula 10 used for suctionlipectomy having a tip 12 and a handle 14 formed at opposite endsthereof. Tip 10 has a hole 16 communicating with a central longitudinalpassage 19 extending through the cannula for connection to a suctionmeans 20 in a well known manner. To remove a desired amount of fat fromfatty tissue 22 (see FIGS. 2 and 3), an incision 24 is first made inskin 26 to expose the tissue. Tip 10 is then inserted through incision24 into tissue 26. By gripping handle 14 to move tip 12 through thefatty tissue in continuous reciprocating strokes (see arrows A and A')while applying suction, fat is surgically aspirated through hole 16 andpassage 18. After a sufficient number of strokes by the surgeon, theoriginal thickness T of fatty tissue is reduced to a lesser thickness T'(see FIG. 3A).

Because suction lipectomy is essentially cosmetic surgery, considerablesurgical skill is necessary to repetitively guide tip 12 in directionsA, A' to leave an even layer of tissue intact This requires guiding tip12 at a constant depth beneath the skin. Otherwise, differentthicknesses of remaining tissue will cause permanent indentations 28 toappear in the skin following surgery (see FIG. 3A), which can be veryunslightly. Unfortunately, however, the results frequently obtained withsuction lipectomy are of the type shown in FIG. 3A, since the surgeondoes not always know or cannot maintain the precise depth at which heguides tip 12 through the tissue. Further, since the surgeon must guidethe tip in directions A,A', there is a tendency during the stroke torotate (arrows B,B') the cannula about its longitudinal axis, causinghole 16 to move above or below the desired depth. Even if the surgeonpossesses sufficient skill to guide tip 12 at constant depth, the largenumber of repetitive strokes necessary for adequate aspiration rendersthe surgical procedure fatiguing to the surgeon, possibly resulting inmomentary loss of control while guiding the cannula.

To remove these permanent indentations 28 or wavy appearance in the skinfrequency caused by use of conventional cannula 10, surgeons generallyrely upon secondary surgery (i.e., suction lipectomy) to removeadditional fatty tissue. Indeed, clinical observations reveal thatsecondary surgical procedures are employed on approximately 20-26% ofpatients initially undergoing suction lipectomy.

To avoid the foregoing problems and reduce the incidence of secondarysurgery, my co-pending U.S. patent application, Ser. No. 651,720, filedSept. 18, 1984, discloses a conventional cannula 10 including a parallelguide bar mounted thereon having a forward guide surface pressed by thesurgeon into constant contact with the skin so that the suction holeremains at constant depth during reciprocation of the cannula throughthe fatty tissue. The guide bar, preferably formed of medical gradestainless steel, is connected at a rear end thereof to the cannula witha threaded bolt secured to the handle and a rear hinge fixing the guidebar to the handle. The guide bar includes a major elevated portionoffset from forward and rear ends of the guide bar in a direction awayfrom the cannula. By providing the elevated portion upon the guide bar,the surgeon is able to grip the elevated portion to facilitatereciprocating movement of the cannula through the fatty tissue andmaintain the guide surface in contact with the skin when performing thesurgical procedure on various parts and therefore different contours ofthe body (i.e., concave, convex or flat).

Friction between the guide surface and the skin surface tends to beminimized by providing a pair of wheels mounted to the guide bar tipwith a cross bolt and nut. The wheels rotate freely on the bolt toprovide tangential rolling contact with the skin surface for lowfriction movement during reciprocating strokes with the cannula.

Adjustment of the distance between the cannula and wheels is achieved bymanipulation of nuts on the handle bolt to pivot the guide wheelstowards or away from the cannula about the hinge. This bolt and hingemechanism constitutes an improvement over the dual bolt mechanismdisclosed in my prior co-pending patent application, Ser. No. 607,714,filed May 7, 1984 now U.S. Pat. No. 4,596,553 wherein spacing betweenthe guide bar and cannula was achieved by adjustment of nuts providedupon both bolts.

In my prior invention described supra, it is necessary to modify thestructure of the cannula handle to include a threaded hole accomodatingthe bolt and a post upon which the hinge is mounted. However, sinceconventional cannulas and handles thereof are not equipped with theabove features, relatively expensive retro-fitting is required tomachine and tap a threaded hole for receiving the bolt and to provide amounting post for the hinge.

It is accordingly an object of the present invention to provide animproved guide bar structure connectible to a conventional cannulawithout requiring alteration of the cannula handle to mount the guidebar thereon.

Another object of the invention is to provide a guide bar that can beuniversally fitted to any type of cannula.

Still a further object is to provide a guide bar that is simple indesign and economical to manufacture.

Still another object is to provide a guide bar structure which, whenattached to a cannula, allows the cannula to be easily guided by thesurgeon at constant depth so that a desired amount of fatty tissue issurgically aspirated while leaving an even thickness layer of tissueintact.

The wheels in my prior invention are generally parallel to each otherand include peripheral surfaces in constant contact with the skin duringreciprocation of the cannula by the surgeon. One of the problems withthis arrangement is that the skin between the wheels and underlyingcannula and soft fatty tissue immediately beneath the skin surface maysometimes bunch up beneath the wheels. This causes the wheels to becometemporarily elevated in a localized area relative to the skin surface.This temporary elevation of the wheels causes a corresponding reductionin depth through which the cannula tip moves through fatty tissuepossibly resulting in wavy indentations 28 to appear in the skin afterthe suction lipectomy procedure.

It is accordingly another object of the present invention to provide animproved guide wheel structure capable of stretching and stabilizing theskin between the wheels and underlying cannula to prevent localizedchanges of the elevation of the wheels relative to skin surfaceoutwardly adjacent the wheels during reciprocating movement of thecannula.

Another object is to provide a guide bar having an adjustment mechanismfor varying the distance between the cannula tip and guide wheelsindependent of the cannula handle.

DISCLOSURE OF THE INVENTION

A device for surgically aspirating subcutaneous fatty tissue from ananimate body, in accordance with a first embodiment of the invention,comprises a cannula having a tip and a handle at opposite ends thereof.The tip is formed with a hole in communication with a longitudinalpassage extending through the cannula. The passage is connectible to asource of vacuum so that suction can be applied to surgically aspiratefatty tissue through the hole when the tip is implanted in tissue. Aguide bar is attached to the cannula for maintaining the hole at apredetermined desired depth within the tissue as the tip is manuallydirected by a surgeon. The guide bar is formed with an elevated portionbetween opposite ends thereof. In operation, only the guide surface isin sliding contact with the skin surface to control the depth of cannulatip; the elevated portion is gripped by the surgeon and allows thesurgeon to manually contact the skin beneath the elevated portion toassist in manipulation of the cannula.

The guide bar preferably has a clamp at one end thereof connecting theguide bar to the cannula handle and an opposite free end terminatingadjacent and spaced from the tip, with a guide surface facing thecannula. The clamp acts as a universal mount to facilitate secureattachment and rapid detachment of the guide bar to the cannula handle.

The guide surface is defined by a pair of wheels rotatably mounted tothe free end of the guide bar to establish a low friction guide surfaceby virtue of rolling contact with the skin. During surgery, this guidesurface contacts the skin surface overlying the fatty tissue to controlthe depth at which the tip removes fat so that an even thickness layerof tissue remains intact upon completion of surgery. Preferably, theperipheral guide surface of each wheel has an inner beveled edgecoacting to stretch the skin between the wheels.

In accordance with a preferred embodiment of the invention, the rear endof the guide bar includes an annular sleeve into which the cannulahandle is inserted and securely held in position by tightening screwspassing through the sleeve. To vary the spacing between the guide wheelsand cannula tip, the wheels are rotatably mounted to the lower end ofheight adjustment bar slidably mounted to the forward end of the guidebar by means of two vertically spaced screws passing through an elongatesot in the adjustment bar. By loosening the screws, the bar can travelvertically towards and away from the cannula tip to achieve the desiredspacing; whereupon the screws are tightened to firmly press theadjustment bar to the forward end of the guide bar. Use of at least twovertically spaced screws within the elongate slot advantageouslyprevents the adjustment bar from pivoting out of vertical alignmentduring suction lipectomy as pressure is applied by the surgeon to theguide bar to firmly maintain the guide wheels in rolling contact withthe skin during reciprocating movement of the cannula.

Still other objects of the present invention will become readilyapparent to those skilled in this art from the following descriptionwherein there is shown and described a preferred embodiment of thisinvention simply by way of illustration of one of the best modescontemplated for carrying out the invention. As will be realized, theinvention is capable of other different embodiments, and its severaldetails are capable of modifications in various, obvious respects, allwithout departing from the invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view of a conventional cannula commonlyused to perform suction lipectomies;

FIG. 2 is a top view of an area of the body on which suction lipectomyis to be performed through an incision formed in the skin;

FIG. 3 is an enlarged fragmentary sectional view taken along the line3--3 of FIG. 2 showing the tip of the prior art cannula of FIG. 1inserted into the fatty tissue through the incision prior to surgicalaspiration;

FIG. 3A is a view similar to FIG. 3 showing typical results obtainedwith the prior art cannula of FIG. 1 upon completion of the suctionlipectomy;

FIG. 4 is a side elevational view of improvements, according to thepresent invention, to the guide bar and guide wheels thereon;

FIG. 4A is a sectional view taken along the line 4A--4A of FIG. 4;

FIG. 5 is a top plan view of the guide bar of FIG. 4;

FIG. 6 is a sectional view taken along the line 6--6 of FIG. 4;

FIG. 7 is a partial detailed view of improvements to the guide wheelassembly; and

FIG. 8 is a partial sectional view of improvements to the guide wheels.

BEST MODE FOR CARRYING OUT THE INVENTION

Guide bar 100 according to the present invention includes forward andrear opposite ends 102 and 104, respectively, and an elevated portionelevated away from the cannula body by being offset from the forward andrear ends in a direction away from the cannula. As depicted in FIG. 4,the rear end 104 is formed with an annular mounting sleeve 108 throughwhich handle 14 of a conventional cannula 10 is inserted and firmlyretained by means of tightening screws 110. Forward end 102 supports,via clamping screws 112, a vertical height adjustment bar 115 rotatablysupporting, at a lower end 115a thereof, a pair of guide wheels 117,119having identical peripheral guide surfaces 120 thereon adapted to makerolling contact with skin 26 during reciprocating movement of cannula 10so that the cannula hole is embedded in tissue 22 at a predetermineddesired depth C.

Sleeve 108, preferably of medical grade stainless steel, is welded orotherwise fixed to the lower surface of rear end 104 and includes apassage 122 of sufficient diameter to receive handle 14 inserted intothe sleeve. A pair of threaded holes 124 formed in the lower surface ofsleeve 108 are adapted to receive a pair of longitudinally spacedtightening screws extending radially into the passage. These tighteningscrews bear against cannula handle 14 to clamp same into tight fittingcontact with the sleeve to prevent axial movement during the suctionlipectomy procedure.

By forming guard 100 with mounting sleeve 108, it will be appreciatedthat the guard is capable of use with virtually any type of commerciallyavailable cannula by simply inserting the cannula handle into the sleeveand thereafter tightening screws 110 to clamp the handle to the guidebar. While the passage 122 is disclosed as being of circularcross-section, it will be appreciated that sleeve 108 can bemanufactured to have an internal cross-section compatible with thecross-section of a cannula handle that may be commercially available. Inaddition, sleeve 108 may be modified in light of the teachings herein solong as it performs the clamping function. For example, sleeve 108 maybe manufactured as a split sleeve having interior clamping surfacesbearing against the cannula handle upon tightening the two halves of thesleeve towards each other and against the handle using screw means.

Height adjustment bar 115, preferably also of medical grade stainlesssteel, is mounted to forward end 102 of guide bar 100 by means ofvertically spaced screws 112 passing through elongate slot 125 formed inupper portions of the adjustment bar. Screws 112 include screw heads112a preferably of larger diameter than the width of slot 125 so thatthe screw heads serve to clamp the adjustment bar to the guide bar upontightening of the screws. The lower end 115a carries guide wheels117,119 rotatably mounted in laterally spaced relationship to each otherupon a cross bolt 69 carrying nut 70. Wheels 117,119 rotate freely onbolt 69 (unthreaded along an intermediate portion thereof) to providetangential rolling contact with the skin surface for low frictionmovement during reciprocating strokes of the cannula.

With reference to FIG. 8, each wheel 117,119 preferably includes, on theperipheral surface 120 thereof, an inner beveled edge 130 inclinedoutwardly and downwardly towards a narrow annular surface 121 of theperipheral edge. The beveled edge 130 assists in stabilizing the skinbetween the wheels during the suction lipectomy procedure by stretchingthe skin so that the cannula tip moves at constant depth through fattytissue 20.

The foregoing description of the preferred embodiment of the inventionhas been presented for purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseform disclosed, and obviously many modifications and variations arepossible in light of the above teaching. The embodiment was chosen anddescribed in order to best explain the principles of the invention andits practical application to thereby enable others skilled in the art tobest utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

I claim:
 1. A device for use with a cannula having a handle and a tip,for positioning the tip of the cannula at a constant depth withinsubcutaneous fatty tissue to surgically aspirate the tissue uponapplication of suction supplied thereto through the tip, comprising aguide element formed with attachment means at a rear end of the guideelement for attachment of the guide element to said handle of thecannula to secure said handle to the attachment means, said guideelement including a guide surface spaced in relation to said tip whenthe cannula handle is secured to the guide element to thereby contact aportion of the skin covering the fatty tissue and maintain the cannulatip at said constant depth during reciprocating movement of the cannulaand guide element with the guide surface moving on and in contact withthe skin.
 2. The device of claim 1, said attachment means including asleeve, wherein said sleeve is welded or otherwise secured to a rear endof the guide element and said clamping means includes at least onetightening screw extending radially through the sleeve to urge thecannula handle into tight contact with the sleeve.
 3. The device ofclaim 2, wherein said sleeve includes an inner cylindrical surfaceagainst which an exterior surface of the handle is clamped.
 4. Thedevice of claim 1, further comprising a height adjustment member fixedto the forward end of the guide element, a lower end of the adjustmentmember defining said guide surface.
 5. The device of claim 4, whereinthe lower end of the height adjustment member includes a pair of guidewheels rotatably mounted thereon, a peripheral surface of said guidewheels defining said guide surface.
 6. The device of claim 5, whereineach guide wheel is formed with an inner beveled edge intersecting theperipheral surface of the associated guide wheel.
 7. The device of claim1, wherein said attachment means is clamped to a front portion of thecannula handle.
 8. The device of claim 1, wherein said guide element isformed with an elevated portion secured to the attachment means with aspacer portion so that the elevated portion extends generally paralleland coextensive to the cannula located forwardly of the handle and thespacer portion extends generally perpendicular to the cannula handle. 9.A device for positioning a tip of a cannula at a constant depth withinsubcutaneous fatty tissue to surgically aspirate the tissue uponapplication of suction supplied thereto through the tip, comprisingguide means mounted on the cannula for maintaining said tip at saidconstant depth as said tip is manually directed by a surgeon through thetissue in reciprocating strokes, said guide means including at a rearend thereof means for clamping the guide means to a handle of thecannula, said guide means including at a forward end thereof avertically movable height adjustment member a lower portion of whichdefines a guide surface adapted to contact a portion of the skincovering the fatty tissue to locate the cannula tip at a constant depthas said tip is manually directed by a surgeon through the tissue inreciprocating strokes, said height adjustment member including means fortightening it to the guide means in selectively spaced locations to thetip.